1. Field of the Invention
The present invention relates to a liquid crystal display device capable of displaying an image with an improved utilization rate of light emitted from a backlight source.
2. Description of the Related Art
For liquid crystal display devices, a mainstream method for displaying a color image is to arrange, side by side, sub-pixels provided for respective color filters of three primary colors of red (R), green (G), and blue (B) and arbitrarily adjust brightness of each of the sub-pixels in order to generate a color by additive color mixing. While this method is capable of a vivid color display, color filters absorb light having a wavelength range other than that of light passing through the color filters, resulting in a loss of the light. Thus, a sufficient quantity of the light may not be ensured, and the light utilization efficiency is low.
As a solution to the above problem, JP-A-2004-294699 discloses a display device including filters (a dichroic filter, a dichroic mirror, a pigment filter causing a bronzing effect, etc.) each having a property to reflect light having a wavelength within a visible range among illumination light emitted by a backlight source, except particular color light to be transmitted through the corresponding filter. Each filter of the above is capable of minimizing a reduction in light intensity, compared with a color filter causing a reduction in the intensity of light having colors other than a predetermined color or colors. This results from the fact that the light reflected by the former color filter is returned to the backlight source, reflected by the backlight source, re-directed to the pixel, and reused. This technique makes it possible, in a liquid crystal display device, to increase the utilization rate of the illumination light emitted by the backlight source.